I have an S90 which takes great pics for a compact p&s and which accompanies all my hiking. This looks better, with a wider wide and a longer tele and an improved sensor. Highly pocketable and packable. But for almost the same money, one can now get a m4/3 camera with a sensor 7-9 times larger that only weighs a few ounces more and has much better image quality for any purpose but the intertubes.

In Japan m4/3 and NEX are already taking a huge bite out of the DSLR market. Now with the new X lenses from Panasonic things will only move faster in this direction. Nikon appears to be working on a m4/3 type camera. If Canon doesn't jump on board soon, it is headed for the dustbin. I've been using Canons for pleasure and work for 30 years and have a slew of beautiful L and top-end ef-s lenses and three bodies. But the weight savings of m4/3 will push me to m4/3 within the next few weeks.

The specs on the s100 are impressive for a compact. Would you expect it take images of nearly the same quality as the entry level m4/3 like the Pana GF3 or the Oly E-PL3? Or because the compact's sensor size is that much smaller means the image quality can't quite compete?

For outdoor and travel purposes, the GPS included in the s100 is a nice touch.

There will always be a gap between what can be done with various size sensors (physics never takes a day off) but how it manifests itself depends on what you're expecting from the camera.

My LX3 experience has been that at low ISOs I can get acceptable enough results to leave the slr at home, so long as I'm not aiming to make big prints or heavily crop the images or shoot action or very low light (or shoot subjects unsuitable for the zoom range). But the roughly 4x larger imager area my dslrs give me provide a much wider performance envelope that can be seen in cleaner image detail, lower noise, greater dynamic range, and higher ISO range, not to mention the ability to shoot much shallower DOFs. (Noting the actual image pixel count is basically the same.) Can't ignore the speed differences either--compacts are very poky in focusing, shutter lag, file write times, etc.

The GF3 and E-PM1 are so tiny that with a pancake lens, they are nearly the same size and weight of an advanced compact and performance-wise, will outperform all compacts lacking a big sensor (a very short list). This is a pretty new development that makes them a viable option for anybody looking for a very good small backpacking camera.

Still, within a fairly narrow performance window any of the latest high-end compacts will get close enough to still warrant consideration. And the old saying about any camera you have being better than one sitting at home still applies.

In sum, there are inescapable advantages to the µ4/3 options but how you use the camera dictates how often you'll run into them. I'll add that ergonomics play a role because using a camera on the go places a premium on a camera that fits well in your hand, is easy to compose with and has the controls you want in the right place.

@Rick, thanks for the very detailed explanation! When you refer to compacts with large sensors, are you meaning something like the Canon G12 as an example? Essentially are you are saying I could expect the GF1 to outperform the s100 or LX3/5 by a sizeable margin but might be about equal to the G12 (or whatever comes next from that line)? Thanks again.

The G12 uses the identical sensor to the S95. It's just dressed in a larger body with more features and the larger lens. Interestingly, it's now roughly the same size and weight as the smallest µ4/3 cameras. A GF1 would hold the same image advantages over it as the others.

In sum, the LX5, XZ-1, S95/100, G12, P7100 and GX200 (all I can think of at the moment) are effectively all the same sensor class. The next step up in sensor size is more of a leap, to the Sigma DPs, Fuji X100 and Leica X1. These compacts have APS-C size imagers (Sigma Foveon is a bit smaller), prime lenses and a big price tag.

YMMV but people are reporting on the preview message boards that the S100 is available from Best Buy - website shows it as pre-order but people are stating they got it in-store. Some stores reported not being able to sell until 10/23 (if you look on the BB site the estimated delivery date window starts the 23 as well) but others stores look like they were selling 5-6 days ago. There's a 10% off coupon floating around as well online and I believe BB coupons commonly come in the mailers from USPS when you move as well.